Quantum dot cellular automata (QCA) is one of the promising technologies for nanoscale implementation. The operation of QCA systems is based on a new paradigm generally referred to as processing-by-wire (PBW). This paper analyzes the defect tolerance properties of PBW when tiles are employed using molecular QCA cells. Based on a 3 times 3 QCA block, with different input/output arrangements, different tiles are analyzed and simulated using a coherence vector engine. The functional characterization and polarization level of these tiles for undeposited cell defects are reported. It is shown that novel features of PBW are possible due to spatial redundancy and QCA tiles are robust and inherently defect tolerant